China has tried to defuse a trade row with the US over wind technology, as the two states moved towards a newly co-operative stance on a range of issues before a summit in Washington.

Officials in Beijing said they were willing to discuss incentives for turbine manufacturers, which the Obama administration described as "illegal subsidies" in a request for talks on the subject at the World Trade Organisation.

The US claims China has given an unfair advantage to domestic companies by channelling hundreds of millions of dollars to them through a special fund established in 2008. The United Steelworkers union is frustrated that this weakens the competitiveness of US firms such as General Electric in a Chinese market that has doubled in size almost every year since 2005 and is now the biggest in the world in terms of generating capacity.

Beijing insists its wind policies are good for the global environment and within trade rules, but was conciliatory. "China will conscientiously study the US request for consultations, and will deal with this in accordance with WTO dispute settlement rules, while retaining our corresponding rights," the Chinese commerce ministry said.

Government advisers were, however, scathing. Professor Pan Jiahua, of the sustainable development research centre at the Chinese Academy of Social Sciences, said the symbolic impact is significant. "At a global level, the US action is terrible. This gives a very bad signal for the world. It says renewable energy technologies should not be encouraged."

Despite this spat, the US and China closed the year on a positive note on many fronts – including trade, military ties, climate change and global security – as they prepared for their presidents' second summit on 19 January. Obama visited China in November 2009.

After a tense year during which US officials, including Barack Obama, openly criticised China, and their Chinese counterparts returned the favour, there was a sudden switch in tone from the US. Instead of portraying China as protectionist or as an "enabler" of North Korea's provocations, US officials were praising China, referring to it again as a responsible partner.

In part, the improved tone reflects Washington's success in leveraging Beijing's desire for a smooth summit to get concessions from China or nudge it toward policies closer to Washington's liking. That said, significant problems bedevil the relationship between the world's sole superpower and a surging counterpart that is both partner and rival. "You've got leaders in the US and in China that want to do everything possible to limit direct confrontation," said Ian Bremmer of the Eurasia Group, a consulting firm, "but structurally, both countries are going to have a hard time avoiding it."

Administration officials commended China for soft-pedaling a proposal to hold emergency talks among South and North Korea, China, Russia, Japan and the US as part of a way to calm the tension in the region. Instead, the officials said China had accepted a US plan that put improving ties between the South and the North ahead of any multilateral talks on the North's nuclear weapons programme.

President Hu Jintao plans to highlight the positive aspects of China's ties with the US. Among other summit events, he is expected to visit a Chinese-owned car parts plant and a joint US-China clean-energy project. China is also considering a request to hold a joint news conference with Obama, something Hu rarely does.

All year, US and Chinese officials have bickered over economic issues, specifically access to China's markets and China's unwillingness to allow the yuan to appreciate against the dollar. But again the tone has shifted. When the US-China Joint Commission on Commerce and Trade wrapped up a meeting in Washington on 15 December, US officials hailed China's co-operation. China said it would open new technology and agriculture markets for US products and would toughen enforcement of intellectual property and software piracy laws.

There's been another U-turn on military relations. China froze those ties in January, after the administration announced plans to sell Taiwan $6.4bn in weapons. Throughout the year, Chinese officers criticised the US.

But on 13 December under-secretary of defence Michele Flournoy met General Ma Xiaotian, deputy chief of the general staff of the People's Liberation Army, and Flournoy was full of praise for her Chinese counterpart. She said that shegave Ma and his entourage the same briefings on the US nuclear, ballistic missile and space postures "that we gave our closest allies".